Many paper-based technical drawings from the past are still valuable for design, manufacturing and maintenance support. Unfortunately, managing these paper-based technical drawings, which are typically kept in paper file archives, is expensive and labor-intensive.
An electronic archival system capable of accessing and managing drawings for immediate electronic retrieval and/or viewing is desireable. An obstacle to creating such a system is that the textual descriptions in the paper-based drawings must be extracted, recognized, and stored electronically. However, manual input of textual descriptions is generally unacceptable because it presents a slow and fallible process.
Several form-reading systems have been proposed or developed for the processing of generic forms. Unfortunately, the processing of technical drawings faces more difficult challenges in that technical drawings are scanned in large image format, and the document data required for processing is often quite large; noise and artifacts due to document aging degrade the quality of scanned images, and the cost for skilled human intervention is significantly high; and technical drawings have a variety of form layouts and context styles, and the information to be read varies from one drawing to another. In order to achieve desirable performance in speed and accuracy, an automated system for electronic archival of paper-based technical drawings is needed.